In general, a typical method of fixing a pipe on the ground or connecting pipes with each other is welding.
However, such the welding method has a disadvantage in that the pipe and the auxiliary members used for fixing the pipe may be all deformed due to the welding heat generated unavoidably at the time of carrying out the thermal fusion.
In addition, the process of carrying out the welding is somewhat complicated, and at the state of finishing the process, it is also found that the horizontal or vertical level of the pipe is not constant, which requires great carefulness in the process.
Moreover, in order to remove the welded pipe, the welding tools are used again or a saw is needed, such that it has disadvantages in that the pipe is not recycled and it requires lots of time and manpower for fixing and removing the pipe structure.
Instead of the welding method, therefore, there are provided another method of fixedly connecting the pipes.
The methods according to the prior arts are disclosed in Japanese Patent Laid-open Publication No. Hei 6-281074 and Korean Utility Model Registration No. 20-0204053, and Korean Utility Model Registration No. 20-0242197.
According to the prior arts, a plurality of jaws are compressed in a central direction with respect to a pipe, while moving to the outside direction thereof by means of a coil spring, which makes the pipe pressurized thus to fix the pipe.
Also, the plurality of jaws are inserted into a jaw coupling which is adapted to be moved to the outside direction by means of the coil spring, such that the jaws press the pipe thus to fix the pipe.
In this case, the plurality of jaws should be arranged horizontally along the outer peripheral surface of the pipe thus to compress the pipe, which can make the pipe rigidly fixed.
In the prior arts, however, the plurality of jaws are not horizontally arranged, which results in the failure of rigidly fixing the pipe.
The reason why fixing the pipe is not achieved is that the coil spring provides different elasticity to the plurality of jaws.
It is generally known that an average compression (elasticity) value for the coil spring formed by winding a spring steel wire several times in a circumferential direction with respect to the pipe is obtained, which exhibits different elasticity values at respective positions around the circumference of the pipe.
In the prior arts where the coil spring is employed, therefore, the spring elasticity values acting with respect to the jaws are different to make the moving distances of the jaws different from one another, such that the jaws are not arranged in a horizontal relation with respect to one another, thus to fail to rigidly fix the pipe.
Additionally, if the pipe after fixing is to be removed, it is forcedly rotated in left and right directions.
In this case, since the jaws are not rotated at the time of rotating the pipe, the outer peripheral surface of the pipe is worn out by the friction against the toothed portions of the jaws.
Thus, the gap between the pipe and the jaws is formed such that if the pipe is pulled forcedly, it is undesirably removed. Moreover, the outer peripheral surface of the pipe is damaged, such that the pipe can be not used again.
Therefore, a novel pipe fixing system, which can provide a generally uniform elasticity value of the coil spring to a plurality of jaws such that the jaws are moved at the same distance, is proposed by the same applicant as the present invention in Korean Utility Model Registration Nos. 20-0269752, 20-0269760, and 20-0347218.
In the prior arts as described above, however, the pipe fixing systems, which are operated to move the jaws through the elasticity of the coil spring thus to compress the pipe, have a disadvantage in that it is difficulty to manufacture the coil spring with the uniform elasticity in large quantities.
This accompanies the problems that products do not have uniform quality and thus, bad products may be made.